Electric lighting fixture



'April 28 1942. A. J. D. OHM

ELECTRIC LIGHTiNG FIXTURE Filed Feb. 21, 1941 4;; w 35- 7/ 2g IP 7 INVENTOR 415:??? J 05m ATTORNEY Patented Apr. 28, 1942 UNITED STATES PATENT OFFICE 2,281,377 ELECTRIC LIGHTING FIXTURE AlbertpJ. D. hm, Bufialo,;N. Y., assign to Markel Electriclroducts, Inc Buffalo,- N; Y.; a corporation of New York Application February 21, 1941, Serial No.r:519",959

Claims.

This invention relates to improvements in electric lighting fixtures and, although not'nec essarily so limited, has characteristics which render it of particular utility in connection with a fluorescent tube fixture of the kind wherein an elongated diffuser is utilized to modify the light emitted by the tube or tubes of the light source.

One object of the invention is to provide a fixture which is so designed as to avoid the ne'- cessity of separate molds for each different length of diffuser which may be required to accommodate different lengths of tubes, this object contemplating a multi-section diffuser built up from sections which are standard with various lengths of diiiusers and which may be assembled in suchnumbers as to obtain any desired length of diffuser.

A further object is to provide for facility in assembling the fixture and in inspecting, re-

moving and replacing the tubes which provide the light source.

A still further object is to provide a fixture which is simple and inexpensive in design and pleasing and attractive in appearance.

The invention is illustrated in the accompanying drawing in which:

Figure 1 is a side elevation of a fixture embodying the features of the invention.

Figure 2 is a horizontal section taken along line 2--2 of Figure 1.

Figure 3 is an enlarged view,-partly in elevation and partly in section, and istaken along line 3-3 of Figure 2.

Figure 4 is an enlarged vertical section taken along line 4-4 of Figure 2'.

Figure 5 is a fragmentary section taken along line 5-5 of Figure 3.

Figure 6 is an enlarged fragmentary section taken along line 6-6 of Figure 1.

The fixture, as illustrated, is of the fluorescent tube type and may be suspended from'the ceiling by a hanger assembly H], rods l'l thereof being suitably connected to the flat top wall l2 of a semi-cylindrical shell [3. The tubes i4 (Figure 4) which provide the light source are mounted in parallel relation and in an arcuate series upon the curved lower wall [5 of the shell and are employed in connection with an elonwhich are transparentand others which are translucent. For example, a rectangularlyshaped, beaded top zone l3 may be transparent, asmay a ribbed bottom wall l9, while side and end walls 20, including a vertically fluted bandlike zone 2 0a, may be, and preferably are, translucent. In accordance with the invention the diffuser comprises an assemblyof pre-formed separable sections which are arranged end-toend and, in the embodiment illustrated,- includes cap i-like end sections 2| and 22 and elongated body'sections 2 3 and 24. The body sections are open at both ends, their inner ends abutting and their outer endsbeing closed by the endsections. A continuous, elongated envelopewhich encloses the, shell I3 and the tubes M is thus provided. At their tops the side walls of the end and body sections terminate in outwardly extending side flanges '2'5 which, in the case of the end sections 21 and 22, join, or form continuations of, end flanges 26, the side and end flanges .of the various sections defining a rectangularly-shaped opening.

The diffuser sectionsare supported in the relation described by spaced longitudinally extending angle members 2-! which are suitably secured at opposite sides of and upon'the top Wall of the shell I 3', the said angle members overhanging thellongitudinal edges of the shell and having vertical side walls 28 which termin'ate in inwardly and upwardly inclined flanges 29. The latter provide seats forthe flanges 25 of the diffuser sections and permit free movement of said sections lengthwise of the angle member-s. In order to prevent the escape of direct light through the joints 30 between the abutting ends'of the diffuser sections, the section 2| is preferably formed with a neck portion 3| (Figures 4' and 6) which enters; the adjacent end of th e body section 23 while the opposite end of the latter section is formed with a neckportion 32 which enters the adjacent end of thebody section 24, the body section Z ibeing similar to the body section 23 and having a neck portion which enters the adjacent end of the end section 22. The neck portions of the diffuser sections mayQas illustrated, be corrugated'or otherwise deformed to provide passages 33 through which airmay' enter and leave the dilfuser to' cool the tubes and associated parts. Preferably bead-like embo'ssments 34 are formed around the; open ends of the diifuser sections, the embossments upon the abutting ends of adjacent sections providing composite ornamental figures having character strokes running parallel with and. at both sides of the joints 3D. The joints are thus effectively obsecured and at the same time the appearance of the fixture is enhanced.

Lengthwise movement of the diffuser sections upon the seats provided by the angle members 2''! is prevented by bail-like straps 35. The latter have legs 36 which are pivotally connected to the terminal portions of the angle members 21 and have transversely extending body portions 31 which are normally located behind the end flanges 26 (Figure 5) of the end sections of the diffuser. The straps 35, however, may be pivoted upwardly about their connections38 with the angle members 21 to the dotted-line position shown in Figure l. The body portions of the straps may thereby be disengaged from, and moved out of the paths of, the end flanges of the end sections. The latter, and the body sections, may, therefore, be moved freely lengthwise of the angle members to detach them and assemble them.

From the foregoing it will be apparent that the angle members 2! provide parallel longitudinally extending guides for the top side flanges of the diffuser sections, that the flanges of the diffuser sections may be caused to enter the guides from either end of the shell and that the body sections are held in place by the two end sections which, in turn, are held against movement oil? the angle members by the straps 35. Facility in assembling the sections of the diffuser and in removing them to enable inspection, removal and replacement of the tubes is thus insured, it being noted in this connection that by removing the caplike end sections 2| and 22 the terminals of the tubes l4 are fully exposed and that the tubes may be detached from the shell I 3 and withdrawn lengthwise without disturbing the body sections 23 and 24. The construction described has the further advantage that a fixture having any desired length of diffuser may be assembled (assuming a shell having guides of the proper length has been provided) by adding the necessary number (one or more) of body sections between the end sections. Any desired length of difiuser may thus be assembled from sections which are standard with all lengths. The use of separate molds for difi'erent lengths of diffusers is thus rendered unnecessary.

It will be understood, of course, that, although fluorescent tubes are illustrated as providing the light source, this is intended by way of example only and that, if desired, any other type of lamp, tubular or otherwise, may be employed instead.

I claim as my invention:

1. An electric lighting fixture of the character described including a body, a light source, an elongated diffuser for modifying the light emitted by said light source, said diffuser comprising a plurality of preformed sections arranged end-toend and including end sections having closed outer ends and open inner ends, longitudinally extending angle members carried by said body which provide spaced guides, said end sections being formed at their closed ends with transversely extending end flanges and with longitudinally extending side flanges which are movable along said guides and which cooperate with the latter to support said sections in a predetermined assembled relation and U-shaped members having legs pivotally connected to said angle members adjacent their ends and normally occupying horizontal positions in which transversely extending body portions cooperate with said end flanges to hold said end sections against movement off said guides, said members being movable about their pivots to release said end flanges and permit removal of said sections from said guides.

2. An electric lighting fixture oi the character described including a shell having top and bottom walls, a light source mounted upon said bottom wall, a diffuser for enclosing said shell and light source comprising a plurality of pro-formed sections, including an end section, arranged horizontally end-to-end to provide an elongated assembly and having longitudinally-extending, outwardly-directed side flanges, said end section having aclo'sed outer end which terminates in an upwardly extending flange, longitudinallyextending, open-ended channel members mounted on said top wall adjacent the longitudinal marginal edges thereof, said channel members extending outwardly beyond said marginal edges, having inwardly-directed flanges upon which the side flanges of said sections seat and permitting said sections to be assembled on said shell and to be removed therefrom only by moving them lengthwise in substantially the same horizontal position and plane in which they are supported, and pivotally mounted means for releasably engaging said upwardly extending flange to hold said sections against lengthwise movement in predetermined positions on said shell.

3. An electric lighting fixture of the character described including a body, a light source mounted on said body, a difiuser for modifying the light emitted by said light source comprising a plurality of pre-formed sections, including end sections, arranged horizontally end-to-end on said body to provide an elongated assembly and having longitudinally-extending side flanges, said end sections having closed outer ends which terminate in upwardly extending end flanges, means carried by said body for providing parallel, longitudinally-extending guides at opposite sides of said body for said side flanges, the side flanges of one of said end sections being adapted to enter said guides from one end and the side flanges of the' other of said sections being adapted to enter said guides from the opposite end, and straps pivotally connected to the terminals of said guides and normally located behind said end flanges to hold said sections in predetermined positions but which are movable with respect to said guides to release positions, said guides permitting said sections to be assembled on said body and to be removed therefrom only by moving them in substantially the same horizontal position and plane in which they are supported and then only when said straps are moved to said last named positions.

4. An electric lighting fixture of the character described including a body, a light source mounted on said body, a difiuser for modifying the light emitted by said light source comprising a plurality of pre-formed sections, including end sections, arranged horizontally end-to-end to provide an elongated assembly and having longitudinally-extending side flanges, and a frame of general rectangular shape carried by said body in which the sections of said diffuser are supported in predetermined positions, said frame having longitudinally-extending side members which provide guides for said side flanges and U-shaped end members having legs which are pivotally connected to the terminals of said side members, said end members being normally located-in positions in which transversely extending body portions engage said end sections but which are movable with respect to said side members to release positions, said guides permitting said sections to be assembled in said frame and to be removed therefrom only by moving them lengthwise in substantially the same horizontal position and plane in which they are supported and then only when said end members are moved to said last named positions.

5. An electric lighting fixture of the character described including a body, a light source mounted on said body, a diffuser for modifying the light emitted by said light source comprising a plurality of pre-formed sections, including end sections, arranged horizontally end-to-end to provide an elongated assembly and having longitudinally-extending side flanges, said end sections also being formed with end shoulders which are located in substantially the same plane as the side flanges, and a frame of general rectangular shape carried by said body and in which the sections of said diffuser are supported in predetermined positions, said frame having longitudinally-extending side members which provide guides for said side flanges and U-shaped end members having legs which are pivotally connected to the terminals of said side members, said end members being normally located in positions in which transversely extending body portions engage said end shoulders but which are movable with respect to said side members to release positions, said guides permitting said sections to be assembled in said frame and to be removed therefrom only by moving them lengthwise in substantially the same horizontal position and plane in which they are supported and then only when said end members are moved to said last named positions.

ALBERT J. D. OHM. 

